Stacking trays



June 12, 1962 w. CLARK 3,038,630

STACKING TRAYS Filed Aug. 8, 1960 2 Sheets-Sheet 1 FIG! J n 12, 96 w. CLARK 3,038,630

STACKING TRAYS Filed Aug. 8, 1960 2 Sheets-Sheet 2 a r; P if T o i mwfiw M WW2...

United States Patent 3,038,630 STACKING TRAYS Wilfred Clark, 99 Portland Road, Birmingham, England Filed Aug. 8, 1960, Ser. No. 48,133 1 Claim. (Cl. 22019) This invention relates to trays constructed of wire and used, for example for the transportation of bread, confectionery and other goods. The invention is particularly concerned with that form of tray which is designed to be stacked, one upon another, with the contents of the trays remaining undisturbed.

This application is a continuation-in-part of my earlier filed copending application Serial No. 690,287, filed October 15, 1957, now abandoned.

The primary object of the invention is to provide a tray of this kind which can be stacked in large numbers and of which the resulting stack is rigid and stable, Without a tendency to develop a tilt in any direction. A further object is to ensure that the load is transmitted from each tray in the stack to the tray below in an evenly distributed manner, avoiding concentration of the load at certain points. A still further object is to provide a wedging action between each tray and the tray below to ensure positive lateral location of the trays with respect to one another.

Yet another object is to achieve the aims set out above in a tray that is economical to manufacture and capable of selling at competitive prices.

Other objects and advantages will be apparent from the following description taken in conjunction with the accompanying drawings, in which:

FIGURE 1 is a plan View of a tray constructed in accordance with the invention;

FIGURE 2 is an end elevation of a pair of trays resting one upon the other;

FIGURE 3 is a partial plan view of one tray;

FIGURE 4 is an isometric view of a corner of the tray; and

FIGURE 5 is a section through a side of the tray on the line 5-5 in FIGURE 3.

Referring now to the drawings in detail, each tray is of open wire construction, comprising a grid of wires crossing one another at right angles and welded, brazed, soldered or otherwise secured together at their intersections. Each tray comprises two horizontal bottom members 1 of stout wire, extending along the two longer sides of the bottom of the tray, the ends of each of these members being turned up to form corner members 2. Thus each of these two wires is of generally inverted U shape, but it will be noted that the corner members *2 are not vertical. Instead they are inclined outwards with respect to a vertical plane extending longitudinally of the tray, and they are likewise inclined with respect to a transversely extending vertical plane.

At intermediate points in the width of the bottom of the tray there are further longitudinal bottom members 3 of stout wire, the ends of these terminating in uprights 4, which, like the members 2, are inclined both sideways and outwards.

An upper horizontal peripheral member 5 of stout wire extends round all four sides of the tray and passes along the outsides of the upper ends of the corner members 2 and uprights 4, being secured to these by Welding. The upper ends of the uprights 4 and corner members 2 lie slightly below the plane defined by the upper surface of the member 5. There is a lower horizontal peripheral member '6 of similar shape to the member 5 and made of the same gauge of wire, this lower member extending around the outside walls of the tray and secured to them in the same manner as the upper member 5. This lower 3,038,630 Patented June 12, 1962 member 6 is disposed in a horizontal plane only a short Way above the plane of the bottom of the tray.

Whereas the upper ends of the corner members 2 are welded right in the corners of the upper horizontal members 5, they are spaced slightly away from the corners of the lower horizontal members 6 along the shorter sides of these members, the inclination of the members 2 with respect to a longitudinal vertical plane being greater than that with respect to a transverse vertical plane, which latter is only sufiicient to take account of the difference in horizontal dimensions between the upper and lower horizontal members.

The main food-supporting surface of the tray is formed by closely spaced wires 7 of lighter gauge than those referred to earlier, these wires 7 extending transversely across the upper surfaces of the members 1 and 3 and having their ends bent up at 8 to form side walls of the tray. These side portions 8 of the thinner wire lie inside the upper and lower horizontal members 5 and 6, and are welded to them, terminating just below the plane of the upper surface of the upper wire 5.

It will be seen from FIGURE 2 that when one tray of the kind described is superimposed upon a second tray of identical form the upper tray is supported by the lower one as a result of the engagement of the underside of the lower horizontal wire 6 of the upper tray with the upper surface of the upper horizontal wire 5 of the tray below. In practice the dimensions of each lower member are slightly less than those of the upper member, as a result of the inclination of the walls of the tray, such that vertical planes containing the outermost surfaces of the sides of the lower horizontal wire 6 pass between the longitudinal centers and innermost surfaces of corresponding sides of the upper horizontal wire 5 and therefore the member 6 of the upper tray does not lie directly on top of the member 5 of the tray below, but on top and slightly inside it. There is thus a certain amount of lateral location achieved by the wedging action of the lower horizontal member of the upper tray in and on the upper horizontal member of the lower tray.

This wedging action is further assisted to a substantial degree by the engagement of the lower portions of the uprights 4 and corner members 2 of the upper tray with those of the lower tray. As a result of the inclination of these members the one side face of each such member on the upper tray nests against the opposite side face of the corresponding member on the tray below and the inclination is arranged to be such that this just occurs as the member 6 of the upper tray engages the member 5 of the tray below.

It will be understood that the manner of engagement described in the preceding two paragraphs ensures accurate location of the upper and lower trays with respect to one another in a horizontal plane. It will be further noted that the load of the upper tray is transmitted to the upper horizontal member of the lower tray in a uniform manner all round, with no concentration of the stress. Thus a large number of the trays according to the invention can be stacked upon one another and the result is a rigid stack, free from any tendency to tilt one way or another. The contents of the individual trays rest protected and undisturbed. If desired, an aperture may be left in one end or side wall, by omitting the uprights 4, or by omitting some of the portions 8 of the thinner wires, thus enabling the contents of the tray to be withdrawn or inserted even when the tray occupies an intermediate position in a stack.

Whilst in the embodiment illustrated I have shown only two intermediate longitudinal base wires 3 between the side members 1, it will be understood that there may be more or less than this number, according to the size and strength of tray required. Likewise, there may be intermediate horizontal peripheral members between the members 5 and 6 if the situation demands this. Furthermore, it will be understood that where I used the terms longitudinal" and transverse these terms have been used in the interests of clarity and are in no way limitative, so that within the scope of the invention is a tray that is square in plan, or which has a greater transverse than longitudinal dimension.

I claim:

A stacking tray of open wire construction comprising: an upper horizontal wire member of substantially rectangular outline to define the top edge of four side walls and presenting a smooth, continuous, upwardly facing load bearing surface; a series of spaced, substantially U-shaped wire frame members each having a web portion to define a base and a pair of uprights lying in opposed side walls, the webs of the outer two members of said series extending along the sides of said base and the uprights of said two members defining corners between adjacent side walls, the uprights of each of the U-shaped wire frame members of the series being inclined outwardly with respect to a vertical plane including the web portion to which such uprights are attached and outwardly with respect to a vertical plane extending transversely of such web portion, all of the uprights of said series of U-shaped members also being secured inside said upper horizontal member and terminating below the horizontal plane of the upper surface of said horizontal member; and a lower horizontal wire member of substantially rectangular outline smaller than the outline of said upper horizontal member by an amount such that vertical planes containing the outermost surfaces of the sides of said lower horizontal member pass between the longitudinal centers and innermost surfaces of corresponding sides of said upper horizontal member, said lower horizontal member being secured about said uprights above the horizontal plane of said base and presenting a smooth, continuous, downwardly facing, load bearing surface so that upon stacking, said lower horizontal member of an upper tray is nestably supported by said upper horizontal member of a lower tray, and the inclination of the uprights of each of the U-shaped wire frame members of the series with respect to the vertical plane including the web portion of such member being such that the tops of such uprights are displaced outwardly relative to the bottoms of the uprights a distance substantially equal to the thickness of the wire of the upright to effect at least partial nesting and wedging engagement of said uprights of the upper tray with corresponding uprights of the lower tray when two like trays are in stacked relation.

References Cited in the file of this patent UNITED STATES PATENTS 2,252,964 Faulkner Aug. 19, 1941 2,438,030 Bitney Mar. 6, 1948 2,523,272 Blum Sept. 26, 1950 2,606,683 Rudd Aug. 12, 1952 2.931,535 Lockwood Apr. 5, 1960 FOREIGN PATENTS 1,176,155 France Nov. 24, 1958 

